Plaster resurfacing vs. aggregate

[mmccully]

Hi,

I'm involved with a homeowners' association that was in the process of resurfacing their community pool with marcite plaster when it was suggested that using an aggregate material instead of plaster would last longer and be less maintenance. I've looked at forums and seen pros and cons about the longevity of aggregate, but so far I haven't seen anything about lower maintenance. In fact, I've seen some things that suggest maintenance of an aggregate could be higher, because algae and/or mold is more likely to form on an uneven surface (such as that of an aggregate) than on a smoother one (such as that of a plastered pool).
Can anyone give me some feedback on the general benefit of aggregate vs. plaster? Also, feedback about specific aggregate materials would help. So far, the recommendations to the association for aggregate have been: Pebble-Tec, Pebble-Sheen, Diamond Brite, Crystal Crete, Hydrozo (marble-like finish), and StoneScape.

Thanks for your help,
Mike

 

[JasonLion]

Although an aggregate finish is expected to be very slightly more prone to algae growth, the difference is not significant in a swimming pool. While not level, an aggregate surface is close enough to level to allow sufficient circulation of water, which will prevent algae growth in any properly sanitized pool. Standard brushes are also able to handle the height difference without problems, so the behavior in practice should be the same.

 

[mmccully]

:-D Thanks for the good info about algae growth.

:?: Do you know if aggregates really last longer? I've seen 5- and 7-year warranties for plaster and 5- 10- and 12-year warranties for different aggregates, which seems to imply that they do last, but then the fine print says warrantied "with proper care". I guess my real question is, do they typically last longer in practice?

Thanks,
Mike

 

[JasonLion]

Practically any finish can be destroyed in a few months or last for decades depending on the care it receives and how carefully the water chemistry is maintained. Plain plaster is the most sensitive to both chemical and physical abrasion. Adding quartz or pebble strengthens the surface and reduces chemical sensitivity. Under typical conditions that should increase the lifetime of the surface.

I have never seen reliable data on actual pool surface lifetimes. The conventional wisdom is that plaster is good, quartz is better, and pebble is best. That makes sense to me based on the chemistry and physical characteristics of the surfaces. How that translates to your particular pool is, however, unpredictable.

 

[mmccully]

Thanks again. What I was looking for was conventional wisdom.

Mike